Abstract:A novel approach is presented for integration of traditional water pinch technology to include detailed waste-water treatment systems models. The theoretical framework as well as examples for practical application of the novel approach will be presented in the paper. The work is carried out within a Research Fund for Coal and Steel (RFCS) ongoing research project aiming at optimal exploitation of resources in integrated iron and steel industries through application of Process Integration methods and technologies. The process models to be embedded in the literature are currently under validation with process data. Results will be presented in the paper together with a selection of case studies on industrial water network optimization problems involving optimal design and simultaneous optimization of the operating conditions of wastewater treatments.